Great thread - thanks for starting it!
I almost always journal - especially on travel pages. I agree with everything Judy said!
Since I have about 24 or 25 scrapbooks with an average of 90 pages each I keep an 8 1/2 x 11 notebook binder with an alphabetical list by last name.
Friends and family can find their name and it lists every scrapbook they are in along with the event or location.
Even my kids can look their name and every layout they are in.